In order to restore the function of a hip joint deteriorated by disease or injury due to an accident or the like, hip replacement arthroplasty for replacing the hip joint with an artificial hip joint has been carried out conventionally. An artificial hip joint stem (hereinafter generally referred to as “stem”) among members constituting the artificial hip joint is the substantially rod-shaped curved member. The stem implanted into a medullary cavity of a thigh bone through the following steps (i) to (iii).
(i) The first step is to make incisions into skin and muscle and resect the head of the thigh bone.
(ii) The next step is to form a first hole serving as a stem shaft and a second hole having the same shape as the stem along the first hole in the medullary cavity of the resulting thigh bone.
(iii) The last step is to implant the stem into the medullary cavity of the thigh bone by driving the stem into the second hole.
The implantation of the stem in the step (iii) among the above steps (i) to (iii) is carried out using a substantially column-shaped stem inserter (hereinafter generally referred to as “inserter”) (for example, refer to non patent document 1). That is, in the step (iii), the stem is implanted by attaching the inserter to the stem and then driving the stem into the second hole by striking a rear end part of the inserter with a hammer.
The non patent document 1 describes the configuration that a screw part located at the front end part of the inserter is screw fixed to a screw hole located in a shoulder part of the stem. Therefore, according to the configuration described in the non patent document 1, the substantially column-shaped inserter is screw fixed from the shoulder part of the stem along the longitudinal direction of the stem. Consequently, the driving of the stem is performed only from immediately above the stem. If the stem driving direction is limited to the direction from immediately above the stem, it may be difficult to drive the stem depending on surgical procedure. If the stem is subjected to forced driving from an oblique direction, the stem and the inserter may bite each other. Hence, there are several risks that it may be difficult to separate the stem and the inserter from each other and both may be damaged. This problem occurs notably with the surgical procedure performed in supine position (lying face up), such as direct anterior approach, in which the abdomen of a patient is liable to create an obstacle to the driving.